1. Field of the Invention
The present invention relates to image pickup apparatuses, image processing methods, and programs, and, more particularly, to an image pickup apparatus, an image processing method, and a program capable of capturing high-quality moving images and still images without requiring separate configurations for processing moving images and still images.
2. Description of the Related Art
Even if a digital still camera and a digital video camera have the same image capturing function, scanning formats adopted for an image pickup device included in the digital still camera and for an image pickup device included in the digital video camera are typically different from each other. A scanning format suitable for capturing still images is adopted for the image pickup device included in the digital still camera, and a scanning format suitable for capturing moving images is adopted for the image pickup device included in the digital video camera.
For example, an image pickup device having a few million pixels or more is used in digital still cameras that mainly capture still images. In order to record high-resolution still images using such an image pickup device, the sequential scanning (progressive format) in which scanning is performed every 1/30 second or more is adopted for the image pickup device.
On the other hand, as a scanning format for an image pickup device used in digital video cameras that mainly capture moving images, the interlaced scanning (interlace format) in which interlaced scanning is performed every 1/60 second is often adopted so as to increase the dynamic resolution of a subject.
Under the above-described situation in which an appropriate scanning format is selected according to the purpose of image capturing, the case in which a single system records both a moving image and a still image will be considered.
Japanese Unexamined Patent Application Publication No. 2002-44531 discloses a technique that allows a user to simultaneously capture a still image and a moving image, as well as, achieve a high-resolution still image.
If a system giving priority to the quality of still images records a moving image without using the technique disclosed in Japanese Unexamined Patent Application Publication No. 2002-44531, the progressive scanning format suitable for capturing still images is adopted for an image pickup device included in the system. That is, a moving image is recorded using images obtained from the progressive scanning in which scanning is performed every 1/30 second or more, whereby a dynamic resolution is decreased.
In contrast, if a system giving priority to the quality of moving images records a still image, the interlace scanning format suitable for capturing moving images is adopted for an image pickup device included in the system. That is, IP conversion is performed upon a moving image portion obtained at the moment when a user gives a still image recording instruction by pressing a shutter button, whereby a single still image can be obtained. In this case, however, since basic image processing performed upon a signal output from the image pickup device such as color difference correction, gamma correction, etc. is not processing suitable for still images, but processing suitable for moving images, the obtained still image is often inferior in quality to a still image captured by a digital still camera.
In order to prevent the deterioration in the quality of still images, there is an apparatus capable of generating a moving image signal and a still image signal from a single output from an image pickup device using two paths, a path in which processing dedicated to moving images is performed, and a path in which processing dedicated to still images is performed. However, since such a single system includes two configurations in which similar processing is performed, a circuit size and power consumption are generally increased. In addition, this leads to a disadvantageous increase in cost.
In order to achieve both a moving image recording function and a still image recording function using a pair of an image pickup device and a single processing path, and, as well as, to obtain high-quality moving images and still images, entire operation switching such as switching between scanning formats for the image pickup device is required.
However, if the entire operation switching is performed, that is, operation switching from a scanning format suitable for moving images to a scanning format suitable for still images is performed when a still image recording instruction is given during moving image recording, no moving image signal can be supplied from the image pickup device during the still image recording. Accordingly, the moving image recording becomes chronologically discontinuous.
In order to prevent the above-described discontinuity, and to obtain a high-quality still image without reducing the quality of a moving image, as disclosed in Japanese Unexamined Patent Application Publication No. 2002-44531, the technique in which an imaging signal having a resolution higher than that of a moving image is output every N times (N≧2) of a moving image capturing cycle has been proposed. However, according to the technique, a high-resolution still image cannot be obtained in a remaining (N−1) frame period in which the high-resolution imaging signal is not output.
It is desirable to provide an image pickup apparatus, an image processing method, and a program capable of capturing high-quality moving images and still images without requiring separate configurations for processing moving images and still images.